Supercharger



Aug. 22, 1944. A. sTlEGgJTz SUPERGHARGER l Filed May 4, 19:58

2 Sheets-Sheet 1 I A. s'nEGLrrz SUPERCHARGER Aug. 22, 1944.

Filed Max 4, 1938 2 Sheets-Sheet 2 .Patented Aug-22, 1944 licat'ionlzlayi, APP. In

This invention relates to regulating devices for superchargers of internal combustion engines. the l supercharger being driven by the engine through 4a..gearing having at least two steps.

A supercharger for an internal combustion engine assists the output of the engine by compressing the combustion v air or the mixture of air and fuel. In the case of aircraft the supercharger is furthermore intended to maintain -the out- 'l put at high altitudes. 'I'he regulation is then eifected by influencing the charging pressure by means of a throttle valve which controls for instance the intake of the supercharger. The

' closed throttle position.

the Alien Property Custodian 193s. sen-m No. rosati ma 1s,

v,4 claim. (ci. aso-n4) throttle valve. *On the other hand, the change.- over from a high supercharger speed to a lower speed must take place at a definite partially .Two arrangements. each according 'to the invention, are shown diagrammaticaily and by way of example in the accompanying drawings,

Fig. l semi-diagrammatically represents a form oi' indirect throttle control in which the invention may be reduced to practice, the device' being shown in one operating position;

Fig. la atically shows' the supercharger ,with its change-speed gear;

Speed transmission for the drive. of the supercharger is so chosen that the desired maximum output is attained' at the desired altitude. Consequently; at lower altitudes and on the ground the intake of the supercharger must be throttled down in order that the maximum permissible charging pressure shall not be exceeded. This is naturallyl uneconomical and disadvantageous `since it is accompanied by losses and increased fuel consumption. -Furthermore, the charging air is heated by the. partially idle running of the supercharger, and the danger of knocking is thereby increased.

These diillculties can be considerably reduced by subdividing the transmission ratio of the supercharger drive by means oi a change-'over gear. The amount of throttling is thus reduced by providing two or more speed ranges for the supercharger.

With a view to ensuring ready and correct Fig. 2 .represents the same modification as Fig. 1, shown in a second operating position, and

Fig. 3l represents a modification of the invention in which the lthrottle is controlled directly by the operator.

Referring nrst to Fig. la, the supercharger 20 is driven fro'in a suitable power supply by way of a variable speed transmission 2| of any conventional construction, and with which itisconnected by wayof a coupling 22. i is a throttle f fr controlling the'amount oi air passing through actuation of the speed variation, with consequent eflicient utilization of the supercharger at all times, there is provided, according to the inven- -tion, an automatic operation which eii'ects the change-over of thegear ratio at the correct instant and in accordance with working conditions. The changingover of the ratio is initiated at the limits of a given range of regulation of the internal combustion engine, within which the prevailing speed of the superchargery may remain, by means connected to the regulating system and which come into action in one or the other operating direction when one or the other limit of the range has been reached.` Since the change-over is mainly dependent upon the position of the throttle determining the charging pressure. the change-over preferably takes place by means of the system operating in conjunction with the control of the tln'ottle.

The change-over point for producing. a higher speed of the supercharger is always definitely de' termined by tbe completely open position of the als the supercharger and the throttle may be arranged for instance as shown in the intake pipe of the supercharger 20.

In the modication of the entire arrangement according to the invention as shown in Fig. l. this throttle iscontrolled by the operator indirectly in the following manner. I isa Sylphon bellows, containing a gas of suitable pressure, this bellows being disposed in a chamber la which is connected by way of a duct lb with the pressure conduit (not shown) which connects the. supercharger with its internal combustion en- .y

gine, so that in case the charging pressure increases the bellows is compressed; while it expands when the supercharger' pressure drops. The point at which bellows I is supported is a control bar le which is formed in the shape of a rack bar and meshes with a pinion i2 iournaled on a naed axle I2a. yThis pinion is yactuated by -the operator by means ot hand-controlled lever Il which. after the operator has moved the lever to the desired extent,- can be set -in a 'ilxed position in `any conventional manner. With the other side oi' Sylphonbellows i is connected the piston valve 2 of aservomotor I which is supplied with pressureiluid from a central conduit 2a by way of the piston valve. 2b, 2b represent the discharge ports for the fluid pressure. The piston rod` 3a of the servomotor piston l is connected by way of connecting rod I with the control arm la of throttle valve I. the latter being cluding the `This interrupts 2 p pivoted at 5b. Thus. if the servomotor piston moves to the right throttle 5 is opened further, if the piston is moved to the left the throttle is closed. Connecting rod l is extended beyond arm Y 5a and is slotted at its end, the slot 6a being of a given length. In this slot is disposed the upper or control end of lever 1 of a toggle joint 1, 8, by means of a. pin 1a. Toggle joint lever l is pivfoted at 1b together with lever Ii, the free end of which latter carries attached to it one end oi' a compression spring ll, the other. end of which spring is attached to the free end of lever 1 at 1c. 'I'he end Gaof levers a distance therefrom, representing the throw of the toggle Joint, is another fixed stop 32h against which the toggle joint shown in Fig'. A2 and to be referred to later on. To the end 8a of lever 8 is pivotally attached a connecting rod which is connected at its other end to a piston valve 9 which controls the servomotor piston -III for the purpose of actuating the gear control rod II. The pressure fluid for this servomotoris supplied at 9a while it is discharged from the ports 9b, 9b. 'I'his gear control rod II as shown in Fig. la, is attached to the actuating arm IIa of the variable speed transmission so that when the piston rod I I moves to the left the gear is thrown into'high speed and when it is moved to the arrangement shown in Fig. 1 operates as follows.

VThe aforementioned slot 6a as will be noted from l connection between 8 so that within given limits determined by the length and position of slot duit of .servomotor piston 3. Thus piston l is moved to,

pulls connecting rod l to throttle l further. This the right and thereby the right and thus opens increases the amount-of air admitted to the supercharger and thereb/y increases the charging pressure and thus the pressure in Sylphon bellows chamber Ia increases slightly. Bincethe operator has operating bar Il,

Sylphon bellows. end and thus to the increased pressure in in the meantime again lock the aforementioned system, in-

is`rigidly held at its right hand bellows contracts due chamber la,

the pressure fluid supply to cylinder space Ib and the piston stops. If. the operatorhas, however, moved theoperating bar Il quite extensively to the throttle B very wide, extension C of the connecting rod I engages at the left hand end of its slot 6a the operating'pin 1a of the toggle joint and snaps the latter through its 'dead center so that it' will assume the position shown in, Fig. 2. Thereby the piston valve d of servomotor I0 is moved tothe rightas shown in Fig. 2, thereby ad- Cnormally rests against a fixed stop 32a. Opposite to this stop and spaced* right it is moved to low speed. The

6a the throttle may, be moved by the operatorwithout actuating the toggle joint. Let us now assume rightin order to openl lustrated in Fig.

mitting pressure fluid to the 'portion Illa of the servomotor III which pushes the piston I0 to the left into the position shown in Fig. 2; Thus the gear shifting bar II moves the lever IIa of the variable speed transmission 2I in Fig. 1a to the left and throws it into high gear, thus changing the speed ofthe supercharger from a lower `toa higher speed.' If, on the other hand, the operator with the entire system now in a condition il- 2, in whichthe throttle is open,

l desires to close the throttle to a considerable extent, he operates his lever I3 the reverse way which brings about a reversal of the action of the' v ventire system andmoves rests in the other position A the change gear bar Il in the other direction and returns the gear shift ,lever to a lower gear as shown in Fig. 1a.

In the modification shown in Fig. 3 essentially the same general construction'of the system is maintained so far as the servomotor III, the toggle joint 1, 8, the throttle and the transmission gear are concerned. In this case. however, the throttle 5 is not controlled indirectly by means of a special servomotor piston I as in Fig. l, but directly by means of the operating bar II by way of two intermediate levers lia and lib, the latter being connected at its other end to the throttle arm la. vThe operators barVI isvpivotally supported on a swinging arm a fixed point. In addition to this arrangement thatthe intakev l is closed a trie more throttle lvery wide beyond 'the' l when the Bylphon l it pulls piston .valve 2 tothe right.

' pilot wishes tween links Iba-and Ib. If

- Thus the same as in that shown in Fig.

the following connection is m'ade for the intermediate levers Ita.4 and--Iib and servomotor Il. The .servomotor piston rod is extended beyond the opposite end of the servomotor cylinder as shown at IIa and necting rod I1a to a The other arm I1c of the Ibell crank is linked to a control bar IB, the other end of which is pivotally connected to the connecting point llc bethe piston III is for instance in the position shown in Fig. 3, the bell crank I1 is held rigid and'thus the operator may actuate the throttle directly by way of links IIa, lib within the range permitted by the lenth of slot 8a. In that case point lic merely describes a' circle determined by the length of rod II. the case of Fig. 1 the toggle joint is not operated. If now, however, theoperator shifts his control bar Il a large amount to the right in order to open throttle B wide for increasing the supercharger output'. which should rather call for increasing the speed of theY supercharger, slotted bar l pulls the toggle joint 1, l to snap through to the opposite position from shifted to the right and consequently servomothe right. shifting the on 2I of the supercharger to a reference to Figs.

power higher speed as described with 1, 2. However, the shifting of the effect of turning bell crank I1 counter-clockwise, whereby connecting bar IC is pushed up 'and straightens out somewhat the links Ila, IIb

which in turn has the effect (assuming that at thattime control bar I3 'has erator) of somewhat closing again throttlel'in order to throttle the air intake in view of the new speed'of thesupercharger in order to maintain the desired pressure. If, on the contrary, the to close the throttlei by a large amount in4 order to reduce the supercharger pressure, the reverse function of the mechanism occurs, namely piston III moves to the right. shifts the transmission crank I1 clockwise, pulling'bar Idown, thereby causing reopening of the throttle l by a certain I3c pivoted at IIb at I" s connected by means of a conbell crank' I1 pivoted at Ilb.4

3, whereby piston valve l is f piston I0 has also been set by the opinto 10W gear. turns belll speed ratio varying means.

Y 2,856,124 amount from the extreme closing position into which the operator had originally pulled it in order to reduce the supercharger pressure.

What is claimed is:

1. A regulating device forthe supercharger of s an internal combustion engine having a throttle higher gear when the throttle is opened wider,

and if the transmission'is in a higher gear it is adjusted into a' lower gear when the throttle is moved toward closing position, said toggle joint having a lost motion connection with said throttle to premit within said givenrange variations of lthe throttle position without actuating said toggle joint and said speed ratio varying means.

2. A regulating device for the supercharger of an internal combustion engine having a throttle arranged in the superchargerl for controlling its charging pressure, a variable speed transmission for ldriving the supercharger, hand-controlled means for varying the throttle position, a servon'iotor for varying the ratio of said transmission and a toggle joint controlled by said throttle and disposed to control the operation of said servomotor to vary the speed-ratio ofsaid transmission in accordance with the varying throttle positions, so that if the transmission is in a lower gear, itis adjusted to a higher gear when the throttle is opened wider, and if the transmission is in a higher gear it is adjusted into a lower gear'when the throttle is moved toward closing position, said toggle joint having a lost motion *connection with said throttle to permit within said given range variations of the throttle position without actuating said toggle joint and said 3. A regulating device for the supercharger of ,an internal combustion engine having a throttle arranged in the supercharger i'or controlling its charging pressure, a variablespeed ton for driving the supercharger, hand-controlled means for varying the throttle position, a servomotor for varying the ratio oi' said transmission and a toggle joint 'controlled bysaid throttle and disposed to control thev operation of said servomotor to vary the speed ratio of said transmission in accordance with the varying throttle positions, so that if the transmission is in a lower-gear, it is adjusted to a higher gear when the throttle is opened wider, and ifl the transmission is in a higher gear it is adjusted into a lower gear when the throttle is moved toward closing position, said toggle joint havingl a lost motion connection with said throttle to permit within said given range variations of the throttle positionv without actuating said toggle joint and said .speed ratio varying means, and means responsive to the supercharger` pressure variation resulting from a supercharger speed change, for slightly moving the throttle in a direction contrary to the direction-in which it was moved by hand to bring about the aforesaid speed change to return the throttle to within said given normal operating range. l

4. A'regulating device for the supercharger of" an internal combustion engine having -a throttle arranged in the supercharger for controlling its j charging pressure, a variable speedl transmission for driving the supercharger, hand-controlled means for varying the throttle position, a servomotor for varying 4the ratio of'said transmission and a toggle joint controlled by said throttle and disped to control the operation of said servomotor to vary the speed ratio of said transmission in accordance withv the varying throttle positions, so that if the transmission is in a lower `mal operating range.

gear, it is adjusted to a higher gear when the throttle is opened wider, and if the transmission is in a higher gear it is adjusted' into a lower gear when the throttle is moved toward closing position, said toggle joint having a lost motion connection with said throttle to permit within said given range variations of the throttle position without actuating said toggle joint and said speed ratio varying means, andmeans controlled by said servomotor for slightly moving the throttle Ain a direction contrary to the direction in which it was moved by hand to bring about a supercharger speed change in a given direction, to -return the throttle to within said given nor- ALBERT sTmGLrrz. 

